000 AXNT20 KNHC 100918 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Tue Aug 10 2021 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 1000 UTC. ...SPECIAL FEATURES... Potential Tropical Cyclone Six is centered near 15.7N 62.2W at 10/0900 UTC or 60 nm SW of Guadeloupe moving WNW at 15 kt. Estimated minimum central pressure is 1010 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Satellite imagery shows scattered moderate to isolated strong convection within 210 nm of the center in the northern semicircle and within 150 nm of the center in the SE quadrant. This system is expected to move across the central Lesser Antilles early this morning and intensify to a tropical storm, then continue W-NW across the NE Caribbean today, across NE Hispaniola Wed, and then continue offshore and parallel to the N coast of Cuba Thu through Fri and across the Straits of Florida and into the SE Gulf of Mexico Sat. Heavy rainfall could lead to flash, urban and small stream flooding and potential mudslides across the U.S. Virgin Islands and Puerto Rico. The greatest threat for flooding impacts will be across the eastern and southeastern portions of Puerto Rico. Tropical storm conditions are expected in portions of the U.S. Virgin Islands and Puerto Rico beginning this afternoon, and in the Dominican Republic by Wednesday. Tropical Storm conditions are possible in northern Haiti by late Wednesday. Wave heights with Potential Tropical Cyclone-Six are forecast to build to near 12 ft today. It has a high chance of becoming a tropical cyclone during the next 48 hours. For more details on Potential Tropical Cyclone Six please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest Potential Tropical Cyclone Six NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov. ...TROPICAL WAVES... The axis of a tropical wave is near 22W from 21N southward, moving westward at 10 to 15 kt. Scattered moderate isolated strong convection is from 07N to 14N between 22W and 28W. The axis of a tropical wave is near 41W from 21N southward, moving westward at 10-15 kt. Scattered showers are noted in the southern end of the wave, from 02N to 06N between 37W and 41W. The axis of a tropical wave is near 77W from 20N aouthward into South America, moving westward at 10-15 kt. Scattered moderate isolated strong convection is noted where the wave intersects the monsoon trough over the SW Caribbean. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through Senegal near 12N16W to 12N20W to 13N30W to 10N46W. The ITCZ continues from 10N46W to 08N56W. Aside from convection described above in the Special Features and Tropical Waves sections, scattered moderate isolated strong convection is noted from 03N to 09N between 42W and 55W. ...GULF OF MEXICO... High pressure of 1019 mb high is centered over the NE Gulf near 28N87W. Ridging from this and the subtropical high dominates the Gulf waters allowing for fairly tranquil conditions. Scattered moderate convection is noted from 24N to 29N and E of 84W. To the southwest, the diurnal trough extends from 22N88W to 18N91W enhancing scattered showers and thunderstorms over the eastern portion of the Bay of Campeche and the Yucatan Peninsula. Light anticyclonic winds are observed in the NE Gulf near the high center. Gentle to moderate east to southeast winds are found elsewhere. Seas ranged from 3-4 ft in the NW Gulf, 1-3 ft in the eastern Gulf. For the forecast, moderate to fresh E winds will pulse off the NW Yucatan Peninsula into the Bay of Campeche each night through Wed night in association with a diurnal trough. Elsewhere, a weak surface ridge will prevail along 30N Tue through Thu. Potential Tropical Cyclone Six is over the NE Caribbean near 15.7N 62.2W 1010 mb at 5 AM EDT moving WNW at 15 kt. Maximum sustained winds 30 kt gusts 40 kt. This system is expected to move across the Straits of Florida Fri night as a tropical storm, then move into the SE Gulf of Mexico Sat. ...CARIBBEAN SEA... Please see the Special Features section for details on newly classified Potential Tropical Cyclone Six. High pressure is present north of the area. Scattered showers and isolated thunderstorms are over the far SW Caribbean near the eastern segment of the East Pacific monsoon trough. Similar activity is over the northwestern Caribbean. Isolated showers and thunderstorms are over the waters between the Windward Passage, across southern coast of Cuba and the Yucatan Channel. Fresh to locally strong trades are over the south-central Caribbean. Moderate to fresh trades are elsewhere over the basin, except over the northwestern Caribbean, where trades are in the gentle to moderate speeds. Seas are 5-7 ft near the Lesser Antilles, 4-6 ft in the central Caribbean, 3-5 ft in the SW Caribbean, and 2-4 ft in the NW Caribbean. For the forecast, fresh to strong trade winds over the central Caribbean will diminish tonight. Potential Tropical Cyclone Six near 15.7N 62.2W 1010 mb at 5 AM EDT moving WNW at 15 kt. Maximum sustained winds 30 kt gusts 40 kt. This system is expected to intensify to a tropical storm today while moving W-NW across the NE Caribbean, then move across the Mona Passage and into Hispaniola early Wed, and then continue offshore and parallel to the N coast of Cuba Thu through Fri and across the Straits of Florida and into the SE Gulf of Mexico Sat. ...ATLANTIC OCEAN... Please see the Special Features section for information on newly classified Potential Tropical Cyclone Six. Three subtropical highs present. One of 1028 mb centered near 35N34W, the other 1028 mb centered near 32N48W and the other of 1026 mb centered near 34N62W. This subtropical ridge dominates the weather regime across the tropical Atlantic. Light to gentle east to southeast winds remain over the waters north of 27N and west of 67W, with moderate to locally fresh trades from 20N to 27N. Seas are 3-5 ft north of 22N and west of 65W, and generally 4-7 ft elsewhere in the discussion waters outside of the area described in the Special Features section. For the forecast W of 65W, Atlc surface ridge associated with the Bermuda- Azores high will persist with axis N of the area for the next several days. Potential Tropical Cyclone Six near 15.7N 62.2W 1010 mb at 5 AM EDT moving WNW at 15 kt. Maximum sustained winds 30 kt gusts 40 kt. This system is expected to intensify to a tropical storm today, then continue W-NW, move across the Mona Passage and into Hispaniola early Wed where it will weaken to a tropical depression. The disturbance will then continue offshore and parallel to the N coast of Cuba Thu through Fri, when it will re- intensify to a tropical storm, then will move across the Straits of Florida and into the SE Gulf of Mexico Sat. $$ AL